This invention relates to (a) a novel process for preparing phosphoroamidates, (b) novel flame retardant polymer compositions containing certain known phosphoroamidates, (c) novel phosphoroamidates and (d) novel flame retardant polymer compositions containing novel phosphoroamidates.
(a) Process
In the past, one method of preparing phosphoroamidates has been carried out by reacting a corresponding phosphorohalidate with an excess of an appropriate amine in an organic diluent. This method is disadvantageous since salts are formed during the reaction which precipite from the organic solution and must be separated and since the only means of scavenging hydrogen chloride formed during the reaction is by the use of excess amine which is quite expensive.
It was also known, of course, that aqueous caustic is a hydrogen chloride scavenger but that knowledge was not believed adaptable to the preparation of phosphoroamidates since it appeared obvious that aqueous caustic would hydrolyze the intermediate phosphorohalidate to phosphoric acid.
(b) Known Phosphoroamidates
The following patents disclose phosphoroamidates prepared from simple aliphatic and aromatic alcohols, phosphorus oxyhalide or thiohalide and an amine:
U.s. pat. No. 2,385,713 U.S. Pat. No. 3,531,550 PA1 U.s. pat. No. 2,912,451 U.S. Pat. No. 3,584,085 PA1 U.s. pat. No. 3,328,494 PA1 U.s. pat. No. 3,254,050 PA1 U.s. pat. No. 3,335,129 PA1 W. german Pat. No. 2,104,569 PA1 U.s. pat. No. 3,256,249 PA1 W. german Pat. No. 2,104,569 PA1 Z-represents the residue of a hydroxyl-containing moiety; PA1 R.sub.1 and R.sub.2 in formula (1) individually represent alkyl, cycloalkyl or aryl, and may be the same or different and, together with their common nitrogen atom represent a 5 or 6 member ring containing oxygen, sulfur or nitrogen or combination thereof; PA1 Nr.sub.1 r.sub.2 in formula (2) represents a 5 or 6-member ring containing oxygen, sulfur or nitrogen or combination thereof; PA1 n represents an integer having a value of 2 or greater and is equal to the number of hydroxyl groups on the original hydroxyl-containing moiety, the residue of which is herein-represented by Z. PA1 R.sub.3 and R.sub.4 individually represent an alkyl group of 1 to 10 carbon atoms or, together with the nitrogen atom, a 5 or 6 member heterocyclic ring; PA1 X represents oxygen or sulfur; PA1 Z represents the residue of a hydroxyl-containing moiety; and PA1 n represents an integer from 1 to 40. PA1 R.sub.1 and R.sub.2, each together with its attached nitrogen atom, represent a 5 or 6 member heterocyclic ring which may additionally contain oxygen, sulfur or nitrogen; PA1 R.sub.5 represents hydrogen, an alkyl group of 1 to 20 carbon atoms, an aryl group, an alkylaryl group or halogen; PA1 R.sub.6 and R.sub.7 individually represent hydrogen, an alkyl group of 1 to 10 carbon atoms, an aryl group or an alkylaryl group; PA1 R.sub.8 represents hydrogen or an alkyl, cycloalkyl, alkaryl, aryl or aralkyl group; PA1 X represents oxygen or sulfur; PA1 A represents a methylene or phenylene group; PA1 B represents hydrogen or ##STR9## Q represents an alkyl group of 1 to 20 carbon atoms, an aryl group, an alkylaryl group, a carbonyl or sulfonyl group, an aliphatic or aromatic ester group or ##STR10## n.sub.1 represents an integer having a value of 0, or 1 to 6 when PA1 n.sub.2 represents an integer having a value of 1 to 50.
U.S. Pat. No. 2,385,713 discloses compounds of the formula (Phenyl-O).sub.m P(O)(NX.sub.2).sub.n wherein X .dbd. H or hydrocarbon and m + n = 3. The compounds are esters of amidophosphoric acids with substituted phenols and have utility as germicides and bactericides. With regard to the present invention, the patent indicates no distinction between the use of primary and secondary amines, contains an enabling disclosure directed only to "diamidophosphates" and, while disclosing certain compounds within the scope of formula (1) of this invention, does not teach the use of phosphorodiamidates as flame retardants.
U.S. Pat. No. 2,912,451 discloses acyclic tetramethylphosphorodiamidates having utility as weed killers. With regard to the present invention, the patent discloses amidation only with dimethylamine, makes only tetramethylphosphoroamidates and does not teach the use of phosphordiamidates as flame retardants, although disclosing certain compounds falling within the scope of formula (1) of this invention.
U.S. Pat. No. 3,328,494 discloses O-(2-naphthyl)phosphorothionates, which may be mono- or diamido substituted, having utility as herbicides. With regard to the present invention, the patent does not disclose a process suing an alkali metal hydroxide and, while disclosing certain N,N'-di-lower alkylamido compounds falling within the scope of formula (1) of this invention, does not distinguish between those compounds the the disclosed diamido compounds and does not teach the use of phosphorodiamidates as flame retardants.
U.S. Pat. No. 3,531,550 discloses certain phosphorus ester mono- and diamides having utility as functional fluids. With regard to the present invention, the patent does not use a process involving alkali metal hydroxide and, while disclosing certain compounds within the scope of formula (1) of this invention, does not teach the use of phosphorodiamidates as flame retardants.
U.S. Pat. No. 3,584,085 discloses the use of certain phosphoromonoamidates as flame retardants for polyurethanes. With regard to the present invention, the patent does not disclose the use of an alkali metal hydroxide and prepares hydroxyalkyl, halophenyl, hydrogen and alkyl-substituted amides which are not within the scope of formula (1) of this invention.
(c) Novel Phosphoroamidates
The following patents disclose phosphoroamidates which are relevant to the compounds of formula (2) of this invention:
U.S. Pat. No. 3,254,050 discloses certain bisphenol biphosphites as flame retardants for various resin systems. With regard to the present invention, the patent does not prepare amidates from bisphenol compounds as defined in formula (2) of the present invention.
U.S. Pat. No. 3,335,129 discloses certain phosphoromono- and diamidates having utility as flame retardants for various resin systems. With regard to the present invention, the patented compounds must contain free hydroxyl groups to provide a reactive site so the compounds may be reacted with the resin systems which they are intended to flame retard. In contrast thereto, the compounds of formula (2) of this invention contain no free hydroxyl groups.
W. German Pat. No. 2,104,569 discloses certain haloalkylamides as flame retardants for polyurethanes. The compounds of formulas (II) and (III) of the patent are distinguished from the compounds of formula (2) of this invention since the compounds of this invention are not haloalkylamide-substituted phosphorus compounds.
(d) Novel Polymer Compositions
The following patents disclose phosphoramidate/resin compositions which are relevant to the polymer compositions containing compounds as defined in formula (2):
U.S. Pat. No. 3,256,249 is relevant to the polymer compositions of this invention which contain compounds of formula (2). The patent discloses hydroxylated phosphoromono- and diamides as flame retardants in various resin systems. In contrast thereto, the polymer compositions of this invention do not contain hydroxylated phosphoroamidate flame retardants.
W. German Pat. No. 2,104,569 discloses haloalkylamide-substituted phosphorus compounds as flame retardants for polyurethanes. With regard to the present invention, the compounds of formulas (II) and (III) of the patent are haloalkylamide-substituted compounds while those of formula (2) of this invention contain no haloalkylamide substituents.